1. Field of the Invention
This invention relates to a pictorial image compression device, and more particularly to a device of the kind described above which is suitable for exhibiting a special video effect by compressing pictorial images.
2. Description of the Prior Art
A method well known in the art and commonly employed in prior art pictorial image compression devices comprises setting beforehand a plurality of specific rates of pictorial image data compression, determining one of the image data compression rates to select one of average image data corresponding to the determined image data compression rate, and writing the average image data in a memory in synchronism with a specific write clock. By the employment of such a method, the image data read out from the memory can be displayed in compressed mode.
However, in the prior art pictorial image compression device, the number of required image data averaging circuits must be equal to that of the image data compression rates, and also the number of required write clocks must be equal to that of the image data compression rates so as to successfully store the image data in the memory. Thus, the prior art device has had such a problem that, in order to achieve the objective of continuous compression of pictorial images, the circuit structure of the device becomes inevitably complex.